LONDON (AP) — Two Boeing 787 Dreamliner planes ran into trouble in England on Friday, with a fire on one temporarily shutting down Heathrow Airport and an unspecified technical issue forcing another to turn back to Manchester Airport.

The fire at Heathrow involved an empty Ethiopian Airlines plane, which was parked at a remote stand of the airport. British police said the fire is being treated as unexplained, and that there were no passengers on board at the time of the fire. Heathrow’s runways reopened after about an hour.

Soon after the fire at Heathrow, U.K. tour operator Thomson Airways confirmed that one of its Boeing 787 Dreamliner planes traveling from England to the U.S. had to turn back after experiencing a technical issue.